Turbocharger with a double-vane nozzle system

ABSTRACT

Disclosed is a turbocharger with a dual-blade nozzle system, comprising a turbine housing, a fixed nozzle ring ( 1 ), a linearly moving nozzle disk ( 2 ), a mid-housing ( 5 ), a rack ( 4 ), rocker arm rods ( 3 ), and a gear ( 6 ), wherein airfoil-shaped fixed blades ( 8 ) are provided on the front end face of the fixed nozzle ring ( 1 ), with blade-type holes ( 9 ) provided between the fixed blades ( 8 ), and the fixed nozzle ring ( 1 ) is sheathed around the outside of the mid-housing ( 5 ) and fixed to the mid-housing ( 5 ) via screws; the linearly moving nozzle disk ( 2 ) is provided on the rear end of the fixed nozzle ring ( 1 ), a group of moving blades ( 7 ) is provided on the front end face of the linearly moving nozzle disk ( 2 ), the moving blades ( 7 ) are movably inserted into the blade-type holes ( 9 ), the rear end face of the linearly moving nozzle disk ( 2 ) is fixedly connected to two rocker arm rods ( 3 ), with the rocker arm rods ( 3 ) inserted into the mid-housing ( 5 ) and engaged with the rack ( 4 ) via the gear ( 6 ). The provision of an additional blade along a nozzle flow passage in the turbocharger with the dual-blade nozzle system can not only reduce the cross-sectional area of the passage, but also separate the original nozzle into two gas passages to reduce the loss of gas flow due to transverse flow; in addition, the gas flow can flow at an optimum gas flow angle according to the original design, so that the turbine can keep working in the high efficiency region.

FIELD OF TECHNOLOGY

The present invention relates to a turbocharger with a double-vanenozzle system, belonging to the field of an automobile device.

BACKGROUND OF TECHNOLOGY

Waste gas discharged from an engine can work for the turbine in thesupercharger, but it can only operate within a narrow high-efficiencyzone. Even through the design point of the vehicular supercharger is setwithin a range of 50-70%, when the engine is operating at full load, theover-speed of the supercharger occurs. Therefore, an exhaust bypassvalve mechanism is arranged on the supercharger in order to improve thereliability while a portion of available energy of gas is wasted.

An effective method to improve the aerodynamic performance of theturbine is to employ a variable nozzle structure, and it is alsogenerally acknowledged and practiced by each of the world-widesupercharger manufacturers. At present, there are three differentsolutions:

The Chinese patent application No. 200710152744.5 filed by HONEYWELLINTERNATIONAL INC, entitled “Vane assembly and method of assembling avane assembly for a variable-nozzle turbocharger”, discloses a methodfor varying the nozzle geometry by changing the vane angle. Such methodhas an advantage that the cross-section area of nozzle is decreased withthe decreasing of the vane angle, the reduction ratio of thecross-section area of nozzle may be up to 50% above. The method has thefollowing shortcomings that, when the nozzle angle alpha (a) is too big(starting state), airflow C″r impacts the convex face of the turbineblade; the nozzle angle alpha (a) is too small (fully load state), theairflow C′r impacts the concave face of the blade (see FIG. 11), so thatthe heat efficiency of the supercharger is reduced regardless ofoperating at low or high working conditions.

The Chinese patent application No. 00819834.9, filed by HONEYWELLGARRETT SA, entitled “Variable Geometry Turbocharger With SlidingPiston”, discloses a simple variable sectional geometry mechanism,wherein the nozzle is composed of a fixing blade and a blade-free airpassage. Adjustable area is only at the side of the blade-free airpassage. Certainly, the adjustable area of 50% is enough. However, theaerodynamic performance is not good. When the blade-free passage isopened, the airflow will pass through both the blade passage and theblade-free passage at the same time. Because the angles of flow of thetwo passages are different, the airflow passed the nozzle will beturbulent, and the flow loss of the airflow is increased, and the heatefficiency of the turbine is reduced.

According to a variable nozzle structure developed by British HOLSETPower Engineering Company, a shielding ring is mounted on the fixednozzle blades. A part of the flow path of the nozzle can be shielded bymoving the shielding ring so as to achieve the adjustment of thecross-section area of the nozzle. Just like the second solution, itsshortcomings are that the airflow passing from the volute to the nozzleinlet is turbulent due to shielding the part of the flow path of thenozzle. It also reduces the heat efficiency of the turbine decreasing.

SUMMARY OF THE INVENTION

Above-mentioned shortcomings are overcome by the present invention whichprovides a turbocharger with a dual-vane nozzle system. A new vane isarranged along and within the flow path of the nozzle, thus the sectionarea of the passage is reduced, and the nozzle is partitioned into twoair passages so as to reduce the cross flow losses of the airflow.Meanwhile, the airflow flows at the originally designed optimum angle offlow, so as to keep the turbine operating in the high-efficiency zone.

In order to solve above-mentioned technical problems, the presentinvention provides a technical solution as follows:

A turbocharger with a double-vane nozzle system, comprising a turbinehousing, a fixed nozzle ring, a linearly moving nozzle disk, amiddle-housing, a rack, rocker arm rods, and a gear, wherein a group ofairfoil shaped fixed vanes are provided on the front end face of thefixed nozzle ring, with blade-shaped holes arranged between the fixedvanes, the fixed nozzle ring is provided with a center hole at thecenter, and sheathed around the circumference of the middle-housing andfixed to the middle-housing via screws, the linearly moving nozzle diskis mounted to the rear end of the fixed nozzle ring, a group of movingblades is provided on the front end face of the linearly moving nozzledisk, and the shape of the moving blade is consistent with that of theblade-shaped hole, the moving blades are movably inserted into theblade-shaped holes, the linearly moving nozzle disk is provided with acenter hole at its center and sheathed around the circumference of themiddle-housing, the rear end face of the linearly moving nozzle disk isfixedly connected with two rocker arm rods, the rocker arm rods areinserted into the middle-housing, each of the rocker arm rods isprovided with teeth at one end and engaged with a rack via the gear, therack is connected to a driving device.

Furthermore, the intake angle of the blade is ranged from about 18 to 24degrees.

Furthermore, 4 to 11 fixed vanes may be employed and 4 to 11 movingblades may also be employed.

Furthermore, the driving device connected to the rack is an air packetexecutor or a solenoid valve.

The turbocharger with a dual-vane nozzle system according to the presentinvention is provided with new blades along the flow path of the nozzle,so as to both reduce the section area of the passage and partition theoriginal nozzle into two air passages, so that the cross flow loss isreduced. Meanwhile, the airflow flows at the originally designed optimumangle of flow, and the turbine operates in the high-efficiency zone. Themoving blades and the fixed vanes are arranged in the same streamwisedirection, thereby avoiding the turbulence caused by the above secondsolution and the third solution, reducing the flow resistance losses. Byincreasing or decreasing the number of the blades, the area of thenozzle outlet can be adjusted. When the moving blades are completelyinserted into the fixed vanes, the reduction ratio of the section areaof the flow path can be adjusted by the thickness of the blade, so thatthe demands of the variable working condition of the engine can besatisfied. Depend on the actual demands, the thickness of blade isdifferent in different turbochargers.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are used for further understanding of thepresent invention and form a part of the description, which explain thepresent invention with the embodiments and is not intended to limit thescope of the present invention. In the drawings:

FIG. 1 is a schematic diagram of the structure of the turbocharger witha dual-vane nozzle system according to the present invention;

FIG. 2 is a schematic diagram of the structure of the linearly movingnozzle disk according to the present invention;

FIG. 3 is a schematic diagram of the structure of the fixed nozzle ringaccording to the present invention;

FIG. 4 is a schematic side view of the fixed nozzle ring according tothe present invention;

FIG. 5 is a schematic diagram of the assembly of the linearly movingdisk and the rocker arm rods according to the present invention;

FIG. 6 is a schematic diagram of the structure of the rocker arm rodaccording to the present invention;

FIG. 7 is a schematic diagram of the structure of the rack according tothe present invention;

FIG. 8 is a schematic side view of the structure of the gear accordingto the present invention;

FIG. 9 is a schematic front view of the structure of the gear accordingto the present invention;

FIG. 10 is a schematic diagram of the assembly of the linearly movingnozzle disk, the fixed nozzle ring and the rocker arm rods according tothe present invention;

FIG. 11 is a schematic diagram of the technical analysis of the firstsolution in the background of the technology.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The preferred embodiments of the invention will be described by takingin conjunction with the accompanying drawings, it should be understoodthat the preferred embodiments illustrated herein is only intended toillustrate and explain the present invention rather than limiting thescope of the present invention.

Embodiment I

It is given that there are eight fixed vanes 8 and eight moving blades7, and the intake angle of the blade, i.e. the blade incidence is 21degree.

As shown in FIGS. 1, 4, and 10, a group of airfoil fixed vane 8 areprovided on the front end face of the fixed nozzle ring 1, blade-shapedholes 9 are arranged between the fixed vanes 8, the fixed nozzle ring 1is provided with a center hole at the center and sheathed around thecircumference of the middle-housing 5 and fixed to the middle-housing 5via screws, a linearly moving nozzle disk 2 is mounted on the rear endof the fixed nozzle ring 1.

As shown in FIGS. 2 and 10, a group of moving blades 7 are provided onthe front end face of the linearly moving nozzle disk 2, the shape ofthe moving blade 7 is consistent with that of the blade-shaped hole 9,the moving blades 7 are moveably inserted into the blade-shaped holes 9.

As shown as in FIGS. 1, 5, 6, and 10, two rocker arm rods 3 are fixed tothe rear end face of the linearly moving nozzle disk 2 via screws, themoving blade 7 on the front end face of the linearly moving nozzle disk2 are inserted into the blade-shaped holes 9 in the fixed nozzle ring 1,the fixed nozzle ring 1 and the linearly moving nozzle disk 2 aresheathed around the circumference of the middle-housing 5, and tworocker arm rods 3 are inserted into corresponding openings in themiddle-housing 5, the openings in the middle-housing are located at theedge of an oil scavenge cavity of the middle-housing 5 and free frominterference with the oil scavenge in the middle-housing 5. Teeth areprovided on the end of the rocker arm rods 3 which engage with a rack 4via a gear 6.

As shown in FIGS. 1 and 3, the fixed nozzle ring 1 are provided withfour round holes in the central part thereof which aligned with thethreaded holes in the middle-housing 5, and fixedly connected to themiddle-housing 5 by tightening screws. After debugging, it is requiredthat the moving blades 7 be able to slide within the blade-shaped holes9 in the fixed nozzle ring 1 smoothly.

With respect to the range of the movement of the moving blades 7, themaximum position is flushed with the front end of the fixed vane 8 whilethe minimum position is flushed with the rear end face of the fixednozzle ring 1.

As shown in FIGS. 6, 7, 8, and 9, both ends of the rack 4 are providedwith teeth, and the end of the rocker arm rod 3 is provided with teeth,an air packet executor pushes the rack 4 upward and downward, since therack 4 is engaged with the gear 6, the gear 6 is driven to rotate, andthe gear 6 is engaged with the teeth on the end of the rocker arm rod 3,thereby the rocker arm rod 3 is driven leftward and rightward. Therocker arm rods 3 are fixedly connected to the linearly moving nozzledisk 2 through screws, thereby the linearly moving nozzle disk 2 beingmoved laterally, and realizing the action of moving the moving blades 7into or from the blade-shaped holes 9.

According to the demands of the variable working conditions of theengine, the linearly moving nozzle disk 2 is moved so that the movingblades 7 insert into the fixed nozzle ring 1 gradually until a completeinsertion being achieved, so that the number of the vanes of the nozzleis increased, or the moving blades 7 are gradually retracted from thefixed nozzle ring 1 until the front end face of the moving blade 7 bemoved to a position flushed with the rear end face of the fixed nozzlering 1, so that the number of the vanes of the nozzle is decreased. Thepurpose of adjusting the outlet area of the nozzle is achieved byadjusting the number of the vanes.

The turbocharger with a dual-vane nozzle system according to the presentinvention is provided with new blades along the flow path of the nozzle,so as to reduce the section area of the passage and partition theoriginal nozzle into two air passages, so that the cross flow loss isreduced. Meanwhile, the airflow flows at the originally designed optimumangle of flow, and the turbine operate in the high-efficiency zone. Themoving blades and the fixed vanes are arranged in a streamwisedirection, thereby avoiding the turbulence caused by the second solutionand the third solution, reducing the flow resistance losses. Byincreasing or decreasing the number of the blades, the area of thenozzle outlet can be adjusted. When the moving blades insert into thefixed vanes completely, the reduction ratio of the section area of theflow path can be adjusted by the thickness of the blade, so that thedemands of the variable working conditions of the engine can besatisfied. Depend on the actual demands, the thickness of blade isdifferent in different turbochargers.

Embodiment II

The difference between the present embodiment II and the embodiment I isthat the driving device pushing the rack upward and downward is asolenoid valve.

Finally, it shall be noted that the above description is the preferredembodiments of the present invention only, it is not intended to limitthe scope of the present invention. Although the present invention hasbeen described in detail with respect to the above-mentionedembodiments, the technical solution disclosed in the embodimentsdescribed above can be modified by the skilled person in the art, orequal substitution of some technical features can be made. Anymodification, equal substitution, and improvement without departing fromthe spirit and principle of the invention shall be within the scope ofthe append claims.

1. A turbocharger with a double-vane nozzle system, comprising a turbinehousing, characterized in that it further comprises a fixed nozzle ring,a linearly moving nozzle disk, a middle-housing, a rack, a gear androcker arm rods, wherein a plurality of airfoil shape fixed vanes areprovided on a front end face of the fixed nozzle ring, with blade-shapedholes arranged between the fixed vanes, the fixed nozzle ring isprovided with a center hole at the center, and sheathed aroundcircumference of a middle-housing and fixed to the middle-housing viascrews, a linearly moving nozzle disk is mounted to a rear end of thefixed nozzle ring, a plurality of moving blades is provided on a frontend face of the linearly moving nozzle disk, and the shape of the movingblade is consistent with that of the blade-shaped hole, the movingblades are movably inserted into the blade-shaped holes, the linearlymoving nozzle disk is provided with a center hole at its center andsheathed around the circumference of the middle-housing, the rear endface of the linearly moving nozzle disk is fixedly connected with tworocker arm rods, the rocker arm rods are inserted into themiddle-housing, each of the rocker arm rods is provided with teeth atone end and engaged with a rack via the gear, the rack is connected to adriving device.
 2. The turbocharger with a double-vane nozzle systemaccording to claim 1, characterized in that an intake angle of the bladeis ranged from about 18 to 24 degrees.
 3. The turbocharger with adouble-vane nozzle system according to claim 1, characterized in that 4to 11 fixed vanes are employed and 4 to 11 moving blades are employed.4. The turbocharger with a double-vane nozzle system according to claim1, characterized in that the driving device connected to the rack is anair packet executor or a solenoid valve.